http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
브레이크 패드의 모재강도에 대한 형상 및 제조공정의 영향 연구
김창석(Changseok Kim),심재환(Jaehwan Shim),배지수(Jisu Bae),현보원(Bowon Hyun) 한국자동차공학회 2019 한국자동차공학회 부문종합 학술대회 Vol.2019 No.5
The physical properties of brake friction materials vary by shape or manufacturing condition. Futhermore, the shape of the lining is tuned to reduce braking noise. The strength of the friction materials is an important characteristic to prevent breakage and is directly related to braking performance. In this study, a method to check the strength of the friction materials and the effectiveness of each control factor on it is proposed through the evaluation of some cases. Also the results were reverified through finite element analysis. Through this study, it was found that the shape and contact area of friction materials greatly affects the strength of it.
Kang, Kyuchang,Bae, Changseok,Yeung, Henry Wing Fung,Chung, Yuk Ying Elsevier 2018 Applied soft computing Vol.66 No.-
<P><B>Abstract</B></P> <P>Large number of object trackers based on particle swarm optimization (PSO) and its variants have been published in the recent decade. However, the majority of algorithms does not perform well when evaluated against the online object tracking benchmark. In the analysis of the existing swarm intelligence based object trackers, pre-mature convergence, loss in particle information and inadequate feature are identified as the factors that hinder the performance of this class of trackers. In this regard, this paper proposes to use the hybrid gravitational search algorithm (HGSA) to increase the utilization of particle information and to facilitate thorough search inside the video frame before convergence. HGSA elegantly combines GSA's gravitational update component with the cognitive and social components of PSO using a novel weight function. The hybridized algorithm acquires the exploitation of past information and fast convergence property typical of PSO, while retaining the GSA capability in fully utilizing all current information. Moreover, the incorporation of deep convolutional feature is proposed to address the inadequacy of the weak hue, saturation and value (HSV) histogram feature. Experimental results using videos from the online tracking benchmark show that the proposed HGSA tracker with deep convolutional feature (DeepHGSA) has increased accuracy of ADSO, the best existing Swarm Intelligence based tracker, by 50.6% and robustness by 56.9% measured by area under curve.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new hybrid gravitational search algorithm (HGSA) is proposed for object tracking in video stream. </LI> <LI> HSGA shows high accuracy rate using videos from the online tracking benchmark. </LI> <LI> Accuracy rate is increased 50.6% with respect to the best existing Swarm Intelligence based tracker. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
유동환경용 FSS 전극 유전체 장벽 방전 구조 플라즈마 발생기의 X-Band 내 RCS 감소 효과
오태주(Taejoo Oh),조창석(Changseok Cho),안욱현(Wookhyun Ahn),육종관(Jong-Gwan Yook),이장재(Jangjae Lee),유신재(Shinjae You),임진우(Jinwoo Yim),하정제(Jungje Ha),배지훈(Gihun Bae),유흥철(Heung Cheol You),이용식(Yongshik Lee) 한국전자파학회 2021 한국전자파학회논문지 Vol.32 No.11
본 논문에서는 주파수 선택 표면(FSS: frequency selective surface)을 전극으로 활용한 유전체 장벽 방전 (DBD: dielectric barrier discharge) 플라즈마 발생기를 제안하고, 이를 기반으로 2차원 평면형 타겟의 레이다 단면적(RCS: radar cross section)을 감소시키는 것을 실험적으로 검증한다. 주파수 선택 표면의 통과대역이 레이다 신호의 대역과 일치하도록 설계함으로써 기존 평행판 커패시터형 DBD 발생기와 달리 발생기를 타겟에 부착하는 과정에서 발생하는 타겟의 RCS 왜곡과 레이다 신호의 편파에 따라 응답이 달라지는 현상을 최소화할 수 있다. 나아가서 유전체 테두리를 활용함으로써 전극과 4.572 mm의 간격을 두고 존재하는 접지면 사이의 공간을 완전 격리시켜 유동환경에서도 안정적인 플라즈마 방전이 가능하다는 것을 확인하였다. 제안된 플라즈마 발생기를 제작하여 플라즈마 최적 방전 및 RCS 측정 실험을 통해 X-band 에서 최대 2.9 dB의 RCS 감소 효과를 얻을 수 있음을 실험적으로 검증하였다. In this study, an frequency selective surface (FSS) electrode of a dielectric barrier discharge (DBD) plasma generator, with a two-dimensional planar target, for radar cross section (RCS) reduction is proposed and measured. The electrode of the proposed plasma generator is based on a cross FSS array conductor. Therefore, it is possible to minimize the amount of RCS change according to the efficient plasma discharge and polarization of the signal from the radar. In addition, a frame of FR-4 dielectric material is placed between the 4.572 mm gap of the ground surface and the electrode to reduce RCS owing to stable plasma discharge in a fluid environment in which the aircraft operates. The proposed plasma generator is fabricated to determine the optimal plasma discharge and RCS measurement. The measurement results showed a 2.9 dB RCS reduction in the X-band.
대면 구조 유전체 장벽 방전 플라즈마의 X-Band 내 RCS 저감 효과
오태주(Taejoo Oh),조창석(Changseok Cho),안욱현(Wookhyun Ahn),김상인(Sangin Kim),육종관(Jong-Gwan Yook),이장재(Jangjae Lee),유신재(Shinjae You),임진우(Jinwoo Yim),하정제(Jungje Ha),배지훈(Gihun Bae),유흥철(Heung Cheol You),이용식(Yongshi 한국전자파학회 2020 한국전자파학회논문지 Vol.31 No.12
본 논문에서는 RCS 저감을 위한 대면 구조 유전체 장벽 방전(DBD: dielectric-barrier-discharge) 플라즈마 발생기를 제안한다. 두께가 0.254 mm 두께인 Ro4350b 기판 위, 아랫면에 16×0.5 ㎠ 크기의 도체가 5 mm의 간격을 두고 서로 마주보고 있는 구조로 타겟에 부착시킴으로써 레이다 단면적(RCS)을 감소시킬 수 있다. 전극이 수직으로 놓일 수밖에 없는 평행판 커패시터 구조의 기존 발생기와 달리 제안한 발생기는 전극이 레이다 신호의 입사 방향과 평행하게 놓이므로 목표물의 RCS에 영향을 최소화하여 플라즈마의 효과를 극대화할 수 있다. 제안하는 대면 구조 발생기를 42층으로 적층한 뒤 20×20 ㎠ 크기의 구리 평판 목표물에 적용하여 X-band 내에서 최대 3.2 dB의 RCS 감소 효과가 있는 것을 실험적으로 검증하였다. 이를 통해 제안하는 플라즈마 발생기의 구조적인 장점과 더불어 RCS 저감 효과 측면에서도 그 우수한 성능을 확인하였다. A dielectric barrier discharge (DBD) plasma generator with a face-to-face multilayer structure for radar cross section (RCS) reduction is designed. The generator includes two electrodes of 16×0.5 ㎠ size, facing each other. Because the electrodes are on the plane that is parallel to the direction of the incident wave, the effect of the generator on the RCS of the target is significantly reduced, particularly when compared to conventional parallel plate-type generators. This simplifies the design procedure for the DBD generator and maximizes the effect of the plasma on RCS reduction. For experimental verification, 42 layers of the proposed generator with a distance of 5 mm between the two electrodes are stacked to reduce the RCS of a 20×20 ㎠-sized copper plate. Experimental results demonstrated a reduction of approximately 3.2 dB in the RCS in the X-band.
Design of Reconfigurable-Wearable Life-Log System by Using Embedded System
Dong-Wan Ryoo,Changseok Bae,Jongho Won,Junseok Park,Jeunwoo Lee 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7
Particularly, embedded systems play the important role in the field of Mobile Devices. Many sensors are mounted on the embedded system in order to satisfy the user requirement or provide many services. But there are apparatus (sensors) which a user doesn't want. Moreover if the system is applied to a new application, the system has to be made again. Therefore the reconfigurable system can have many advantages according to a need. In the presented paper, the reconfigurable life-log system was developed for life-log service by using embedded system. A system can be comprised of selected apparatus or sensors by users. The users can select the preferring functions and reconfigure the system. We designed of two kinds of wearable life-log systems. The first is belt type wearable life-log system, the second is headband type wearable life-log system for physiological signals. In our developed system, the temperature sensor, accelerometer, illumination sensor, and GPS are used as the apparatus.